Why is Beijing Sinking?

Over the past decade or so, Beijing has been growing at a breakneck pace. In 2000, the official Chinese census recorded 13,569,194 residents; by 2010, that number had grown to 19,612,368 – a growth rate of 44%.

Though that decade was particularly remarkable in terms of growth, it’s far from anomalous. In fact, since the 1960s, the city has grown at an average rate of 20% per decade, meaning that the land upon which it is built has undergone significant stress. A new study published in the journal Remote Sensing has found that this stress has resulted in the city sinking at a considerable rate over the last century.

Built upon watery foundations

The city is built upon large reserves of permeable rock, which allows groundwater to exist underground and hydrate the Chinese capital. However, the rapid growth in population, along with the industrial boom and urban development which has accompanied this, has caused this groundwater to be used up more quickly than it is replenished.

Indeed, the city has suffered from a water shortage for some time – an issue that was alleviated slightly back in 2008 when neighbouring Heibei province provided surplus supplies to the capital. However, another unexpected effect of the dwindling water reserves is that the city has been sinking – apparently since the 1930s!

The new study utilised GPS and satellite images to monitor topographical alterations to Beijing’s geography, studying data from between 2003 and 2010. They found that the city is indeed sinking into the ground, and at an alarming rate of 11cm per year.

As is to be expected, the most heavily developed area of the city (the financial district, laden with skyscrapers and high-rise buildings) is the region sinking at the fastest rate. This has caused concerns that the diminishing water supplies could harm the infrastructure of Beijing and do irreparable damage to buildings, roads and railways.

Another environmental problem to contend with

The rapid descent of Beijing is just another environmental problem which the city’s authorities will have to deal with. In addition to having scarce water supplies, water quality has also been an issue for the Chinese capital. This is primarily caused by lax standards in the industrial water market, an area now being placed under increased scrutiny.

What’s more, China’s ongoing struggle with air pollution is a well-documented problem. The nation has long been known as one of the biggest polluters in the world, with an exorbitant population and exponential growth in industry being responsible for huge amounts of contaminants being spewed out into the atmosphere. Last year, Beijing announced the first ever red alert in air quality in the city’s history, highlighting the seriousness of the problem.

Fortunately, the authorities have been taking a proactive approach to air pollution control (APC) in China today, implementing comprehensive plans intended to achieve ambitious targets in the coming years. However, the city of Beijing and the country of China as a whole still face an enormous challenge in addressing their environmental problems, especially if they want to avoid the capital sinking without trace.